Electron tube



E. B|UcHE 2,034,174

ELECTRON TUBE Filed Sept. 24, 1932' March 17, 1936.

INVENTOR ERNST /R" HE ATTORNEY 4 Patented Mar. 17, 1936 PATENT OFFICE ELECTRON TUBE Ernst Briiche, Berlin-Reinlc kendorf (0st), Germany, assignor to Allgemeine Elektrlcitatz Gesellschaft, Berlin. Germany, a corporation of Germany Application September 24. 193:, Serial No. 634,705 In Germany September 25, 1931 3 Claims. (01. sac-41.5)

The present invention relates to electron ray tubes and principally to a cathode ray tube.

An important object of the present invention is to provide ways and means adapted to cause an electron-ray pencil to be deflected out of its direction into another direction without requiring the use of either electrical or magnetic fields. An arrangement of this kind ofiers particular advantages in connection with the construction of electron-ray tubes whether these be employed for oscillographic, sound-film or television work,

for instance, in connection with the photographic recording of an oscillographed action where the direct light produced by the electron ray in deviated position is unable to impinge upon the photographic plate or film.

A device of the said sort, according to the in-- vention, is realizable by a metallic tubelet which has a width of 2 mm., for example, and the requisite curvature. The small diameter tubelet is kept at anode potential or at another suitable but diiferent voltage. If the electron-ray pencil emanating from a hot cathode is-caused to pass into the metallic tubelet as far as feasible coaxially therewith, in the presence of slight volumes of gas, the pencil of electrons will be guided along the curvature of the tubelet-and will leave the latter in the changed direction.

One special merit of this arrangement may be regarded as residing in this fact that a magnetic field will not influence the electron-ray penbil inside the metallic tubelet. Moreover, a tubelet of the said sort may serve the purpose of causing the electron-ray pencil to proceed exactly ire-determined direction, for example, along the tubular axis of an oscillographic tube.

Practical arrangements could be made in such a way that the curved tubelet is placed inside the bulb of a Braun or. cathode ray Fig. 1, of the drawing while fled form of arrangement as the drawing may be used.

To refer now to the drawing, and first to Fig. 1, thereof, there is supported inside a curved vessel 8 a heated cathode 2. Opposite the cathode member 2 is disposed a curved metal tubelet 3 in such a way that, upon application of'a suitable voltage to the tubelet by way of the lead 6, the electrons issuing from the cathode will be guided into the opening 5 of the said tubelet. What issues then from opening 6 is a pencil of electrons travelling along the dotted line, and this electron pen oil may be rendered visible in the usual manner by means of the fluorescent screen which is positioned in the path thereo It will thus be seen in other cases a modithat the direction of the pencil at the outlet end of the tubelet 8 diifers from the original sense of flow of the electron pencil at the place where it entered the tubelet. This-pencil is influenceable by ways and means well known in the prior art electrostatlcally, e. g., by the aid of deflector plates 8 or else may be controlled magnetically where desired.

The flared or enlarged inlet opening 5 of the metallic tubelet consists most conveniently of a difllcultly fusible metal such as molybdenum, while the rest of the tubelet may consist of some other metal such as copper which has its interior surface silver-coated, if desired. Instead of a metal tubelet an insulating tube which rendered conductive in its interior surface could be employed. Such a structure might, for example, be an internally silver-coated glass tubelet.

In the embodiment here cited by way of example, the tubelet 8 serves and acts at the same time as the anode element for the tube. In its stead, however, a distinct anode could be mounted between the .heated cathode and the tubelet.

The tubelet could then be kept at the same potenthe way shown by the modified arrangement in Fig. 2. In the modified form tube consists of two vessels connected by way of a fleiziblecopper tube 9. contained within the vessel It is a -hot cathode it which gives off electrons. This vessel is closed by means of a cap i3, e. g., of copper, into which the flexible copper tube 9 is fitted. Applying to tubelet 9, for instance, by way of lead It, a suitable voltage of, say, a few hundred volts, the electrons will be deflected towards the opening I! the cathode-ray and they emerge from tubelet 9 at the opening I! thereof and enter into most suitably is shut'likewise by means of a cop-' per cap ll. The electron pencils may then be rendered visible by the fluorescent screen 20.

The said copper tubelet 9 may be bent into any formation with the result that the electron-ray pencil is caused to flow-in any desired direction. It would thus be possible, for instance, to bend the pencil in such a direction that it will not be acted upon by whatever fields may .prevail in space, say, by terrestrial magnetism.

This form of construction of the cathode-ray l0 and which are of the electrons is dethe vessel H which tube moreover oflers the advantage that deflector means such as deflecting coils I! may be applied at any desired proximity to the pencil of electrons and at the same'time at greater distance irom the place oi. generation of the pencil, while yet being located in the outside space. Another advantageous feature may be regarded to reside in that when the tube is connected with a pump, an appreciable pressure diflerence ismaintalnable between the two spaces; for instance, space Y or vessel is may be kept substantially ireeirom gases" wmle inside space H Blight volumes or gas may be present.

Inside tube it ,ss well known in the earlier art;

deflector plates '69 designed for insuring electrostatic deviation may be mounted.

Having now described the invention what .is claimed is the following: I

i. A cathode ray device comprising a pair oil. independent envelope members each maintained at a 'difierent pressure, a source of cathode rays contained within one envelope; a fluorescent screen contained within the other envelope, a-

vflexible tubular anode member connecting the two envelopes and having an opening substantially adjacent the source 01 electrons in one envelope and an opening at the: other end in the so as to seal the tubular anode within each ves sci.

3. A cathode ray device comprising a. source of electrons. a flexible tubular anode member to cause the electrons to be drawn from the source in the form of an electron pencil, a funnelshapedmouth portion for said anode member, said mouth portion being constituted of a difficultly fusible material and constituting an inlet opening for said tubular anode and positioned substantially adjacent the source of electrons for receiving the emitted electrons, and a fluorescent viewing screen in the path the electrons issuing from the flexible tubular anode member.

ERNST nations. 

